Device for locking the steering spindle of a vehicle

ABSTRACT

A lock for irrotationally locking a motor-vehicle steering column ( 1 ) enclosed by a tubular housing ( 6 ), said lock comprising a locking element ( 2 ) displaceable to-and-fro between a locked and a released position and further a drive motor ( 3 ) driving the locking element ( 2 ). For greater compactness, to offer enhanced security against theft, and to leave unhampered the telescoping of the steering pillar composed of steering column ( 1 ) and tubular housing ( 6 ), further to reduce the danger of knee injury in case of accident, the locking element ( 2 ) is mounted in the vicinity of the steering-wheel side end ( 4 ) of the steering column ( 1 ) inside the tubular housing ( 6 ), and the drive motor ( 3 ) is mounted next to the foot-space side end ( 5 ) of the steering column ( 1 ), and the drive motor ( 3 ) cooperates with the locking element ( 2 ) through a connecting element ( 8 ) arranged inside the tubular housing ( 6 ).

[0001] The invention relates to a lock for irrotationally locking amotor-vehicle steering column enclosed by a tubular housing, said lockbeing fitted with a locking element displaceable in a to-and-fro mannerbetween a locked and a released position and with a drive motor drivingsaid locking element.

[0002] A number of different designs already are known for meansirrotationally locking motor-vehicle steering columns.

[0003] Illustratively, as regards one design of the prior art, thelocking element and the said drive motor are configured at the lowersteering-column end within a common housing. The steering column runsthrough the associated tubular housing, and through an opening in ametal floor panel of the motor vehicle and through said common housingscrewed onto the metal floor panel on the side away from said tubularhousing. The locking element encloses the steering column and issupported in axially displaceable but irrotational manner in said commonhousing and is fitted with locking teeth which may be made to mesh withmatching locking teeth of the steering column. Said drive motor is anelectric motor affixed to the inside of said common housing andcooperates by a mechanical linkage or by a lever with said lockingelement (EP 0 265 826 B).

[0004] In another known design of the kind of lock discussed herein, thelocking element and the drive motor are mounted close to one another andoutside the tubular housing enclosing the steering column. The lockingelement is in the shape of a bush and is mounted on the tubular housingin an axially displaceable manner and is fitted with at least oneresilient locking tooth that can be made to mesh with rigid lockingteeth of the steering column. Said drive motor is an electric motorexternally affixed to the tubular housing and by means of a cam-collarcooperates with the locking element in order to displace the latteragainst the force of a helical compression spring enclosing the steeringcolumn in a manner such that the locking element's locking tooth can bedisengaged from the steering column's locking teeth to allow rotation ofthe steering column. The cam-collar is rotatably supported on thetubular housing and is fitted with circumferential teeth meshing with apinion affixed on the shaft of the electric motor (DE 195 00 682 C).

[0005] Again a design of the above discussed type of lock is knownwherein the locking element and the drive motor are configured near eachother in a common housing through which the steering column runs. Thelocking element consists of a shaft rotatably supported inside thehousing and fitted with two radially projecting locking protrusions. Theshaft runs tangentially relative to a locking ring which is affixed tothe steering column and which is fitted with locking teeth with whichthe shaft's locking protrusions can be made to engage. The drive motoris an electric motor affixed in the housing and cooperating via agearing unit with said shaft (DE 196 21 326 C).

[0006] The objective of the present invention is a lock of the initiallymentioned kind which is characterized by compactness, by offeringextraordinary vehicle theft-protection, by unhampered ability totelescope of the steering pillar composed of steering column and tubularhousing, and by preserving the driver in the event of accident from kneeinjuries because it is located outside the region containing the knees.

[0007] This goal is attained by the features of claim 1. Advantageousfurther designs of the lock of the invention are stated in the remainingclaims.

[0008] An illustrative embodiment of the lock of the invention isdescribed below in relation to the attached drawings.

[0009]FIG. 1 is a side view in partly longitudinal section, the lockingelement being in its locked position, and

[0010]FIG. 2 is a view similar to that of FIG. 1, but with the lockingelement being in its released position.

[0011] The shown lock is used to irrotationally lock a motor-vehiclesteering column 1 and it is fitted with a locking element 2 which can bemoved to-and-fro between the locked position of FIG. 1 and the releasedposition of FIG. 2 and is driven by drive motor 3.

[0012] The steering column 1 is enclosed between its two ends 4, 5 by atubular housing 6. The motor-vehicle steering wheel is mounted on theend 4 of the steering column 1 on the left in FIGS. 1 and 2. The end 5of the steering column 1 shown on the right in FIGS. 1 and 2 isconnected near the motor-vehicle foot space to said vehicle's steeringgear unit.

[0013] The locking element 2 is mounted in the vicinity of thesteering-wheel side end 4 of the steering column 1 within the tubularhousing 6. The drive motor 3 is mounted next to the foot-space side end5 of the steering column 1, namely outside the tubular housing 6. Thedrive motor 3 cooperates by a connecting element 8 with the lockingelement 2, said connecting element being mounted inside said tubularhousing 6.

[0014] The locking element 2 is in the form of a bush and encloses thesteering column 1, being supported inside the tubular housing 6 in anaxially displaceable but irrotational manner, as a result of which thelocking element 2 is prevented from rotating inside the tubular housing6 but can move to-and-fro along the steering column 1. The lockingelement 2 is conical at the left end 9 as shown in FIGS. 1 and 2 and isfitted at the end 9, which tapers toward the steering-wheel side end 4of the steering column 1, with circumferentially equally spaced outerlocking teeth 10 cooperating with corresponding locking teeth 11 of thesteering column 1.

[0015] The locking teeth 11 of the steering column 1 are provided on acollar 12 affixed to said steering column 1. The collar 12 is fitted atthe end 13 adjacent to the locking element 2 with a conical borehole 14receiving the conical end 9 of the locking element 2. The locking teeth11 are circumferentially evenly spaced in the borehole 14 of the collar12, said borehole 14 tapering like the end 9 of the locking element 2toward the steering-wheel side end 4 of the steering column 1.

[0016] The locking element 2 is loaded by a helical compression spring15 toward the collar 12 of the steering column 1. This helicalcompression spring 15 encloses the steering column 1 at that side of thelocking element 2 which is away from the collar 12 and rests by one endagainst the end surface 16 of the locking element 2, which end surface16 faces the foot-space side end 5 of said column 1, and it rests by itsother end against a ring 17 affixed in the tubular housing 6.

[0017] The connecting element 8 between the drive motor 3 and thelocking element 2 is in the form of an elongated plate which runsparallel to the steering column 1 within the tubular housing 6 and issupported in an axially displaceable manner in a groove 18 of thetubular housing 6. The drive motor 3 cooperates with the right end 19shown in FIGS. 1 and 2 of the connecting element 8 which in turncooperates with the left end 20 shown in FIGS. 1 and 2 by means of aU-shaped pivoting bail 21 with the locking element 2.

[0018] The U-shaped pivotable bail 21 is received in an external annulargroove 22 of the locking element 2 and encloses the locking element 2from above in FIGS. 1, 2. The pivotable bail 21 comprises two side legs23 and a crossbar 24 linking the two legs 23. By its adjacent end 20,the connecting element 8 acts on the two free ends 25 of the legs 23.The pivotable bail 21 is pivotably supported on the tubular housing 6 atthat side of the locking element 2 which is away from the connectingelement 8, namely by means of a protrusion 26 projecting from the centerof the crossbar 24 and pointing away from the legs 23 and entering anaperture 27 of the tubular housing 6. On that side where the connectingelement 8 and the helical compression spring 15 are situated, andbetween their free ends 25 and the crossbar 24, the two legs 23 each arefitted with a convex boss 28 resting against the adjacent side surface29 of the annular groove 22.

[0019] The drive motor 3 is an electric motor cooperating by means of agear unit 30, a slider 31 and a two-arm pivot lever 32 with theconnecting element 8. The drive motor 3, the gearing unit 30, the slider31 and the pivot lever 32 are mounted in a common housing 33 which isaffixed externally to the tubular housing 6, that is at its foot-spaceside end 34. The pivot lever 32 is pivotably supported on an arbor 35mounted in the housing 33 in such manner as to rest by one end 36against the slider 31 and to engage by the other end 37 in a recess 38on the adjacent end 19 of the connecting element 8.

[0020] The shown lock irrotationally locking the motor-vehicle steeringcolumn 1 operates as follows:

[0021] The steering column 1 is shown locked in FIG. 1. The lockingelement 2 assumes its locked position wherein its locking teeth 10engage the gaps between the locking teeth 11 of the steering column 1,as a result of which this steering column 1 is coupled to the tubularhousing 6 within which it is irrotational. To unlock the steering column1, the drive motor 3 is turned ON in such a way that, by means of thegear unit 30 and the slider 31, it shall pivot the pivot lever 32 in thedirection of the arrow A. In the process the pivot lever 32 displacesthe connecting element 8 in the direction of the arrow B and saidconnecting element 8 in turn pivots the pivotable bail 21 in thedirection of the arrow C. In the process, the pivotable bail 21displaces the locking element 2 in the direction of the arrow D againstthe loading from the helical compression spring 15 into its releasedposition wherein the locking teeth 10 of the locking element 2 aredisengaged from the locking teeth 11 of the steering column 1, and as aresult the steering column 1 now can be rotated inside the tubularhousing.

[0022] Consequently the state shown in FIG. 2 has been achieved. Inorder to relock the steering column 1, the drive motor 3 will be powerednext, as a result of which the pivot lever 32, the connecting element 8,the pivotable bail 21 and the locking element 2, biased by the helicalcompression spring 15, respectively are displaced in the direction ofthe arrow A′, B′, C′ and D′ and thereby the state of FIG. 1 is restored.

1. A lock for irrotationally locking a motor-vehicle steering column (1)enclosed by a tubular housing (6), said lock being fitted with a lockingelement (2) displaceable to-and-fro between a locked and a releasedposition and further with a drive motor (3) to drive the locking element(2), characterized in that the locking element (2) is mounted in thevicinity of the steering-wheel side end (4) of the steering column (1)within the tubular housing (6) and in that the drive motor (3) ismounted next to the foot-space side end (5) of the steering column (1)and in that the drive motor (3) cooperates by means of a connectingelement (8) arranged inside the tubular housing (6) with the lockingelement (2).
 2. Lock as claimed in claim 1, characterized in that thelocking element (2) assumes the shape of a bush and is fitted withlocking teeth (10) and encloses the steering column (1) and is axiallydisplaceable in a manner that in the locked position its locking teeth(10) lock the steering column (1 ) to the tubular housing (6).
 3. Lockas claimed in claim 2, characterized in that the bush-shaped lockingelement (2) is supported in irrotational but axially freely displaceablemanner inside the tubular housing (6) and in that its locking teeth (10)cooperate with matching locking teeth (11) of the steering column (1).4. Lock as claimed in claim 1, 2 or 3, characterized in that theconnecting element (8) directly cooperates with the locking element (2).5. Lock as claimed in either of claims 2 and 3, characterized in thatthe connecting element (8) cooperates by means of a U-shaped pivotablebail (21) with the bush-shaped locking element (2), said bail (21)enclosing said locking element (2) and being pivotably supported on thetubular housing (6) at the center of its crossbar (24) on the side ofthe locking element (2) away from the connecting element (8), theconnecting element (8) acting on the free ends (25) of the two legs (23)of the pivotable bail (21) and the legs (23) in turn acting betweentheir free ends (25) and the crossbar (24) of the pivotable bail (21) onthe locking element (2).
 6. Lock as claimed in one of the above claims,characterized in that the locking element (2) is spring-loaded into thelocked position.
 7. Lock as claimed in claim 6 jointly with claim 2, 3or 5, characterized in that the bush-shaped locking element (2) isbiased by a helical compression spring (15) into the locked position,said spring (15) enclosing the steering column (1) and resting on onehand on the tubular housing (6) and on the other hand on the lockingelement (2).
 8. Lock as claimed in one of the above claims,characterized in that the drive motor (3) is an electric motor.
 9. Lockas claimed in one of the above claims, characterized in that theconnecting element (8) is an elongated plate which is axiallydisplaceable parallel to the steering column (1).
 10. Lock as claimed inclaim 9, characterized in that the drive motor (3) cooperates by meansof a two-arm pivot lever (32) with the connecting element (8), saidlever (32) being pivotable about an arbor (35) affixed to the tubularhousing.
 11. Lock as claimed in claim 10, characterized in that thedrive motor (3) and the pivoting lever (32) are mounted in a commonhousing (33) which is externally affixed to the foot-space side end (34)of the tubular housing (6) and which is provided with the pivot arbor(35) of the pivoting lever (32).